Research On Real-Time Simulation And Testing Platform For A Seamless Automatic Mechanical Transmission For Electric Vehicles

In recent years,multi-speed transmission has become more widely used as a development of the single-speed transmission in the powertrain of electric vehicle.In our study group,researches of a novel seamless two-speed automatic mechanical transmission(AMT)are conducted to utilize the multi-speed transmission on the electric vehicle.For this purpose,a real-time simulation and testing platform was conducted for developing and testing of the AMT.Firstly,the establishment of an electric vehicle simulation model is introduced and a prototype of the two-speed AMT is developed.The structure of the vehicle model used in the simulation model was also designed,including the parameter configuration of the vehicle and the vehicle powertrain system.The mathematical model of the vehicle and the AMT were implemented based on MATLAB/Simulink.To establish the overall structure scheme of the test platform,a frequently used Vcycle design was applied in this study to analyze and build the key components of the test platform,including the platform's measuring and driveline system.Based on MATLAB/Simulink with its Simulink Real-Time,this study proposed a solution for designing of a real-time simulation and control system of the test platform by using a standard desktop PC as a real-time simulator.The hardware design and selection was completed according to the analysis of the driveline system requirements.In summary,the scheme of the test bench was constructed based on the two three-phase AC induction motors together with the frequency controllers that employing with the capacity of direct torque control,in which the energy from one motor is feedback to another through DC bus for consumption.In order to study and develop the real-time simulation and control system of the test platform,based on the simplified analysis of the structure of the test platform drive system,this study proposed an equivalent dynamic model of the test platform driveline system and established its dynamic equations.The load torque,which the load motor needs to provide,was determined according to the vehicle dynamics as an input for the motor.The parameters of the key mechanical components of the test platform are also selected and verified.Finaly,the required real-time simulation and testing of the transmission were implemented,mainly including the shift control of the transmission and the vehicle driving cycle of the platform.The test results were also analyzed as a verification of the designed system function and the control accuracy of the driveline system of the platform.